Gunmen shot dead a Venezuelan judge at a street barricade in the latest fatality of two months of anti-government unrest that has seen at least 61 people killed, authorities said on Thursday.

Nelson Moncada, 37, was killed and stripped of his belongings as he tried to get away from the roadblock on Wednesday night in Caracas' El Paraiso district, the scene of regular clashes, the state prosecutor's office said.

It was unclear why Moncada had been targeted.

There was violence around the capital on Wednesday after security forces forcibly broke up tens of thousands of opposition supporters marching on government offices downtown, and skirmishes continued into the night.

Some local news sites said the incident in which Moncada was killed appeared to be a robbery while others noted he had presided in the controversial case of Bassil Da Costa, a protester shot during another wave of anti-Maduro demonstrations in 2014.

Victims from the violence then and this year have included supporters on both sides, bystanders and members of the security forces. El Paraiso has seen nightly clashes between demonstrators, pro-government gangs and National Guard soldiers.

Venezuela's opposition is demanding new elections to replace the unpopular socialist president whom foes accuse of wrecking the OPEC nation's economy and of becoming a dictator.

Maduro, 54, calls them coup-mongers seeking his violent overthrow with U.S. support akin to the short-lived toppling of his predecessor Hugo Chavez in 2002.

While the state prosecutor's office has noted 61 deaths in protests and lootings that began in early April, Venezuela's state ombudsman Tarek Saab put the figure at 65.

At a news conference, he noted there had been arrests or warrants issued for 35 members of the security forces over the fatalities. Rights campaigners say 3,000 people have also been arrested, of whom nearly half remain behind bars.

Venezuela's pro-government Supreme Court ordered opposition leader Henrique Capriles on Wednesday to avoid roadblocks in the Miranda state that he governs, or face jail.

Miranda includes part of the capital Caracas, and the volatile towns of San Antonio de Los Altos and Los Teques, where anti-government street barricades have been common.

The 44-year-old lawyer narrowly lost a 2013 vote to Maduro after Chavez's death from cancer, and has been at the forefront of this year's protests, calling for civil disobedience.

Authorities have already barred Capriles from running for new political posts for 15 years, on allegations of "administrative irregularities" that he denies, potentially hobbling another bid to run in 2018 when the next presidential vote is due.